macologic implications.
1. Higher doses of sedatives. Be aware of patients who use marijua-
na as a self-prescribed sedative before surgery. The use of marijuana,
especially immediately before surgery, can change the doses you'll
need for sedation. A study (osmag.net/BF6kwN) in the March 2009
European Journal of Anaesthesiology found that patients who rou-
tinely use marijuana will require substantially higher doses of propo-
fol for satisfactory clinical induction when inserting a laryngeal mask.
2. Vasodilation. Just like anesthesia, cannabis has a tendency to lower
both blood pressure and heart rate. This will attenuate the effects of
anesthesia, resulting in patients being under longer and having a hard-
er time waking up.
3. Airway obstruction. Just like a nicotine smoker, pot smokers have
an overactive airway, which can cause coughing and lead to aspiration
during and after surgery. Smoking marijuana before surgery also
increases mucus production in the respiratory tract.
4. Drowsiness. Marijuana might increase the amount of drowsiness
some drugs cause. Examples include benzodiazepines such as
lorazepam (Ativan) or diazepam (Valium), barbiturates such as pheno-
barbital, narcotics such as codeine, some antidepressants and alcohol.
5. Increased risk of bleeding. Marijuana may increase the risk of
bleeding when taken with drugs that increase the risk of bleeding.
Some examples include aspirin, anticoagulants (blood thinners) such
as warfarin (Coumadin) or heparin, antiplatelet drugs such as clopido-
Safety
S
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